US Patent 7757834 Workpiece presentment to a processing device

A workpiece presentment system and associated method for workpiece presentment with a pick and place device is provided. The system includes a pair of parallel stationary rails, and first and second shuttle rails respectively disposed adjacent first and second ends of the stationary rails. Each shuttle rail is independently moveable laterally to a longitudinal alignment with a selected one of the pair of stationary rails. A control circuit is configured to circulate only two pallets simultaneously in the same rectangular path of travel to load trays to the pallets on one of the stationary rails while presenting the trays to the pick and place device on the other stationary rail.